(CNN) -- The violent standoff between Iraqi insurgents and U.S. Marines in Fallujah has created an atmosphere of unpredictable danger.

Christian Science Monitor correspondent Scott Peterson has been embedded with the 1st Marine Expeditionary Unit for the past week at Camp Fallujah. He spoke with CNN's Paula Zahn by phone about why the military chose to stand back and why the strength of the insurgency has been a surprise.

PETERSON: Well, I think [the military] felt that, if [it was] able to continue pursuing pinpoint attacks, then [it] eventually would prevail without having to actually roll into the entire city.

ZAHN: You have covered other war zones before. Describe to us the danger you have witnessed in the last couple of days and how it compared to other violence you have witnessed.

PETERSON: Well, I think that this conflict is one that is incredibly dangerous, not only for the Marines themselves, because this is ... an urban environment, but also I think for the journalists who are covering it.

In many cases, we are embedded with Marines who are right there on the front line, along with troops who are on the front line. It serves two purposes. Of course, we get to see what's going on. But it also means that we are right there with them. We have, you know, a feeling for the kind of stresses and the kind of dangers that that front line brings with it.

Also the type of insurgency, the kind of risks that there are in Iraq generally, in terms of hostage-taking, which has now become a tactic of various ... anti-American groups, whether they be [Shiite], whether they be Sunni, like we're seeing in Fallujah, there are those kind of things. And compared, for example, to Somalia, which was a story that I covered a lot in 1992 and 1993, Somalia was a place where always there would be shooting every single night, practically 24 hours a day.

Everybody had a gun. And whenever the shooting calmed down, you thought, wait a minute, maybe something's going to happen. In Iraq, there's almost no kind of peripheral shooting that you ever hear. And you never know what's going to go on or what is going to happen or where you are until you get blown off the road. And I think that's what the Marines are facing, too, on a daily basis, especially with these explosive devices, roadside bombs, things like that, that the insurgents are just very, very clever about installing and delivering casualties.

ZAHN: So, given the unpredictability of the attackers, realistically, what kind of precautions could you as journalists take, or even Marines take, to stay alive?

PETERSON: Well, the Marines, of course, are getting better and better at eyeballing these improvised explosive devices, as they call them, IEDs. But [the Iraqis] are very clever, too ... in terms of how they create them.

Sometimes, you see a curb along a road that it looks like it's a piece of concrete. In fact, it has got a 155 millimeter howitzer round in it, which can cause a huge amount of damage. There have been so many explosions and casualties and injuries caused to Americans by these types of weapons that, in some cases, U.S. forces here, especially the Marines, have actually begun to modify their armor.

They're now using the -- they're now using Kevlar shoulder patches and shoulder guards to cover the parts of the extremities that are particularly prone to getting injured when some these IEDs and roadside bombs explode. They're using now new ballistic glasses which have become standard issue. And they have made orders for thousands of these in the last couple of months to make sure -- because they were seeing so many eye injuries from these things.

So they have had to modify also in a very quick manner the type of warfare that they're seeing here, which, in this kind of environment, I don't think they've seen in -- at least in kind of recent institutional memory.

ZAHN: According to "The Los Angeles Times," there have been so many Marines wounded in Fallujah that there is actually a backlog of Purple Hearts. What does that do to the morale of troops?

PETERSON: Well, it's surprising, to be honest. ... I have spoken to a lot [of Marines] who have been engaged in some of these firefights. In fact, I was in one of the combat surgical rooms where they were working on a couple of these guys.

Two of them had been ambushed, not where the main fight is going on tonight, but their unit had been ambushed east of Fallujah. And seven people rolled in. There were two that had gunshot wounds. And they pulled a huge slug, a bullet, out of the leg of one of the Marines. And another one had a bullet wound right through the back.

And, amazingly, they were trying to convince their commanders that they were ready to go and go back out. I have been really surprised at ... the high degree of morale that these Marines have shown. Remember, they have only been here for a month and a half. Many of these units that are here now engaged in the initial invasion last year and were in Iraq for several months.

Now they're back. But they seem to be engaged. They're taking casualties. But it's really surprising. You don't see much head-dragging or anything like that. I mean, you know, what you see is kind of more encouragement for these guys.

And, for example, the one who had the gravest -- the bullet in and out through his back -- was trying to convince his commander that he'd be back. And his commander actually promised him that his spot was still going to be there. Another soldier who was injured in that huge firefight yesterday who I spoke to earlier this morning, he wanted to get back out there. But the only problem was, was that half his shoulder was missing around his firing arm.

But he was convinced he would be able to sit there on a roof and not have to run anywhere and he could contribute that way. So it's been surprising. But ... the Marines that are here certainly appear to be geared up for whatever the future holds.